Synchronous pressure-controlling device.



G. C. FARMER. SYNCHRONOUS PRESSURE CONTROLLING DEVICE.

APPLICATION FILED DEO. 27, 1910.

Patented Apr. 1, 1913.

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CLYDE C. FARMER, OF CHICAGO, ILLINOIS, ASSIGNOR TO TI-IE WESTING'I-IOUSEAIR BRAKE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN-SYLVANIA.

SYNCI-IRONOUS PRESSURE-CONTROLLING DEVICE.

Specification of Letters Patent.

Patented Apr. 1, 1913.

To all LU/wm 25 may concern:

Be it known that I, CLYDE C. FARMER, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Synchronous Pressure-ControllingDevices, of which the following is a specification.

This invention relates to fluid pressure controlling devices and is inthe nature of an improvement upon the construction covered in Patent No.1,031,173, dated July 2, 1912.

Apparatus embodying my invention is adapted more particularly to beemployed in connection with equipments now commonly applied to electrictraction cars and comprising an air compressor, a main reservoir, acont-rol pipe line adapted to be supplied with fluid under pressure fromthe main reservoir through a feed or reducing valve device at apredetermined degree of pressure less than the maximum main reservoirpressure, a train brake pipe leading from the brake valve, and anautomatic brake equipment having the usual brake cylinder, triple valve,and auxiliary reservoir and adapted to be operated by variations in thetrain brake pipe pressure. Where two or more cars so equipped areconnected up in a tra-in, the train brake pipe and the control pipe lineare connected by couplings with similar pipes on the adjacent car and bymanipulating the brake valve on the head car, air is taken from thecontrol pipe line to recharge the train brake pipe and maintain thepressure therein against leakage. In order to avoid excessive operationof any one compressor it is highly desirable that each compressor, onthe cars so equipped, should supply its proportionate amount of air tomaintain the pressure in the control pipe line when air is suppliedtherefrom to the train brake pipe and this is one of the objects of theconstruction covered in my patent hereinbefore referred to.

The apparatus shown in this patent comprises broadly a main supplyvalve, a piston for operating said valve to supply fluid from the mainreservoir to the control pipe line, a regulating valve for releasingfluid from one side of said piston for operating same, and a diaphragmsubject to the opposing pressures of the control pipe line and asubstantially const-ant fluid pressure, such as that of the signal pipeline, for operating said regulating valve.

By employing a regulating diaphragm on each car which is subject to thesame constant pressure on all cars, it will be seen that when thecontrol pipe line pressure is reduced all of the feed valves throughoutthe train are operated simultaneously to supply fluid from thecorresponding main reservoir to the control pipe line. Thus everycompressor operates to furnish its quota of air and excessive operationof any one compressor is avoided. In releasing the brakes after anapplication, however, it may happen that air is taken from the controlpipe line at such a high rate through the brake valve on the leading caras to cause the control pipe line pressure on said car to drop fasterand to a lower degree than the pressure in the cont-rol pipe on theother cars and as the close proximity of the leading feed valve to thebrake valve causes this feed valve to be effected by the low controlpipe pressure, a larger quantity of air is discharged from the leadingmain reservoir than from any of the others, thus tending to causeexcessive compressor operation on the leading car.

The principal object of my present invention is to obviate the abovedifficulty and for this purpose I provide means for increasing the loadon the regulating diaphragm of the feed valve device on the leading car,so that this particular feed valve device shuts olf at a control pipepressure a few pounds less than the normal pressure. Thus the completionof the recharge of the train pipe and auxiliary reservoir is effected bythe compressors on the other cars and eX- cessive operation of thecompressor on the leading car is prevented. Furthermore, the feed valvedevice on the leading car requiring a greater drop in pressure in thecontrol pipe to open same than on the other cars, it will be evidentthat this leading feed valve will not open to supply ordinary trainbrake pipe leakage, but that such leakage will be provided for by theoperation of the other feed valves.

In the accompanying drawing; Figure 1 is a diagrammatic view showing theair brake equipment of two cars coupled together with my improvementapplied thereto; and Fig. 2 a sectional view of a feed valve deviceembodying my invention.

As shown in Fig. 1, the equipment for each car comprises a motor-drivenair compressor 1 for supplying air to a main reservoir 27 a train pipe8, triple valve 4, auX- iliary reservoir 5, and brake cylinder 6, acontrol pipe line 7 and a signal pipe line 8. Brake valves 9 are locatedat opposite ends of the car and are connected to the train brake pipe 8and control pipe line 8 in the usual manner, said pipe lines having theusual couplings at opposite ends of the car.

The feed valve device embodying my invention may be constructed as shownin Fig. 2 in which a casing 10 is provided having a piston chamber 11containing piston 12 and valve chamber 18 connected by pipe 14 to themain reservoir 2 and containing the supply slide valve 15. The usualfeed valve regulating portion is also provided comprising a diaphragm 16subject 0n one side to the pressure of an adjustable spring 17 and onthe opposite side to the pressure of t-he control pipe line, the passage18 supplying fluid from the control pipe to said diaphragm. Thediaphragm 16 is adapted to operate a valve 19 for controlling theventing of air from piston chamber 11 through a passage 20 to thecontrol pipe passage 18. As in lthe prior application hereinbeforereferred to, a second regulating diaphragm 21 is also provided which issubject on one side to a constant pressure such as signal line pressuresupplied through pipe 22 and o-n the opposite side to control pipepressure contained in passage 18. The diaphragm 21 is adapted to operatea valve 22 for controlling the venting of air from piston chamber 11 tothe control pipe passage 18. i

According to. my present invention, a double seated movable abutment 28is provided having one side constantly exposed to the pressure on top ofvalve 22 and contained in piston chamber 11, the stem of the valve 22being loosely fitted to permit flow of air from the passage 20 to saidabutment 28. The opposite side of the abutment 28 is subject to thepressure of a coil spring 24 and the chamber 25 at this side of theabutment is connected to a pipe26, leading to a main reservoir supplypipe 27 which latter pipe extends to the opposite ends of the car and isprovided with cocks 28 adjaout of the cock at one end when the cock isopen at. the opposite end supplying main reservoir pressure.

Within the movable abutment 28 and adapted to bear on the top of thestem of valve 22 is a spring cap 8O subject to the pressure of a spring81.

`A check valve 82 may be inserted in the pipe 22 and a small reservoir88 may be connected to that portion of the pipe 22 adjacent the feedvalve device so as to more fully insure the maintenance of a constantpressure on one side of the diaphragm 21, the reservoir serving toincrease the volume of air act-ing on the diaphragm, s o that ordinaryfluctuations in pressure in the signal pipe line will not effect anysubstantial variation in pressure on said cliaphragm.

rllie signal pipe line may be charged from the main reservoir 2 througha pipe 84 containing a reducing valve 85 for limiting the degree ofpressure in the signal pipe. And in order to feed air to the signal pipeonly on the leading car a cut out cock 86 may be provided which isopened on the leading car and closed on all the other cars. 1f desired,the pipe 84 above the reducing valve 85 may be connected to pipe 28adjacent the double check valve 29, and in such case, it will be seenthat air is only Supplied to the signal pipe when one of the cut outcocks 28 is open and as this cock is open only on the head car, the sameresult is secured as by employing the cut out cocks 86.

In operation, the spring 17 of the ordinary regulating device isadjusted to a degree less than the standard pressure carried, say aboutten pounds, so that under normal conditions the regulating diaphragm 16does not control the operation of the feed valve, said diaphragm onlyoperating when the synchronous regulating portion of the feed valvefails to act for any reason.

On the leading car, the co-ck 28 at the forward end is opened so thatfluid from the main reservoir is supplied to chamber 25 thus balancingthe fluid pressure constantly acting on thev opposite side of theabutment 28. The spring 24 then shifts the abutment to its inner seatand by the movement of same the spring cap is caused to engage the stemof valve 22 and the spring 81 is thereby compressed somewhat, thusincreasing the differential required to open the valve 22 by thepressure of the spring 81. The tension of spring 81 is preferably suchthat the valve 22 will close at two or three pounds less than the normalpressure carried in the control pipe. On the other cars, the chamber 25is open to the atmosphere through cock 28, so that the fluid pressure onthe opposite side of the piston valve 28 is sufficient to overcome thektension of spring 24 and shift the abutment 28 to its outer position.The pressure fof spring'l is thus'removed from the valve 22 andconsequently on cars other than the leading car, the diaphragm 21operates the valve 22 in its usual manner when the convtrol pipe linepressure falls a fevv ounces.

It .will now be evident that with my im provenient, the completion ofthe recharge of the train pipe and the auxiliary reservoirs as Well astrain pipe leakage is taken care of by the compressors on the cars otherthan the leading car, so that the leading car compressor is not operatedto an eX- cessive degree, and thus more uniform pump operation issecured.

Having noiv described my inventiomwhat I claim as new and desire tosecure by Letters Patent, is:

l. The combination with a source of fluid under pressure and a lowpressure receptacle, of a feed valve device adapted to normally supplyfluid from said source to said low pressure receptacle at apredetermined degree of pressure less than the pressure of said sourceand means for loading said feed valve device to thereby cause same todeliver air to the low pressure receptacle at a maximum pressure lessthan the normal degree of low pressure.

2. A feed valve device comprising a valve and piston for supplying fluidto an outlet, a regulating valve and diaphragm adapted to normallyeffect the operation of said supply valve and piston upon apredetermined reduction in the outlet pressure, and means for increasingthe load on said diaphragm to thereby effect the operation of saidsupply valve and piston at a maximum pressure less than the normalmaximum outlet pressure.

3. A feed valve device comprising a valve and piston for supplying fluidto an outlet, a regulating valve and a diaphragm subject to the opposingpressures of the outlet and a substantially constant pressure for normally effecting the operation of said supply valve and piston to supplyfluid to said outlet and maintain a predetermined degree of pressuretherein, and means for applying an additional load 0n said regulatingdiaphragm to render the same operative only at a degree of outletpressure less than the normal operative pressure.

de. A feed valve device comprising a main Copiesl of this patent may beobtained for supply valve and piston, a regulating diaphragm subject onone side to the outlet pressure, a valve operated by said diaphragm forvarying the pressure on said .supply piston, a 'Valve piston normallysubject on one. side to fluid pressure and on the opposite side to thepressure of a spring, a load device operated by said valve device uponsupplying fluid to the spring side thereof for increasing the loadacting on said diaphragm.

5. A feed valve device comprising a valve mechanism operated by varyingthe pressure thereon for supplying fluid to an outlet, a regulatingvalve mechanism governed by the outlet pressure for varying the pressure0n said supply valve mechanism, a load device, and a movable abutmentnormally subject to the opposing pressures of a spring and fluidpressure and operated upon supplying fluid under pressure to the springside to cause said load device to exert its load upon said diaphragm.

6. The combination with a plurality of feed valve devices and a commonoutlet receptacle supplied with fluid under pressure thereby, of meansfor normally effecting the simultaneous operation of all the feed valvesto maintain the outlet pressure at a predetermined degree, and a devicefor rendering one of the feed valve devices operative only at adifferent predetermined degree of pressure.

7. The combination With a plurality of feed valve devices and a commonoutlet receptacle supplied with fluid thereby, each feed valve devicecomprising a supply valve device and a regulating valve mechanismsubject to the opposing pressures of the common outlet receptacle andthe pressure in common maintaining receptacle for controlling theoperation of said supply valve device, of means for altering the load onthe regulating valve mechanism of one feed valve device to cause saidfeed valve device to operate at an outlet pressure different from thatof the other feed valve devices.

In testimony whereof l have hereunto set my hand. l

CLYDE C. FARMER. Witnesses:

T. A. HEDENDAHL, B. S. JARNAGIN.

ve cents each, by addressing the Commissioner of Patente, Washington, D.C.

